I have some decent earphones that I bought for about $15 and an ok set of speakers that I use to check if my music is mastered well, but I'm getting the feeling that they are starting to limit me in music production. So I am getting some quality headphones for $100+. Any recommendations before I start researching myself?

Subsonic_Noise

Take it from an audio engineer: the big companies we trust are, among others, Beyerdynamic, Ultrasone and AKG. If you want clear sound and isolation isn't an issue, go for open headphones. Closed ones will have stronger bass and isolate better, but sounds less clear. Avoid Beats and Skullcandy at any price. They're overpriced and don't deliver quality that would suit the price, at all. If closed is okay with you, go for the Ultrasone Pro series. The only open headphones they have are the Edition 10s, but those are around 3000-4000€, so pretty much out of your league. :L For open ones, go for Beyerdynamic or AKG. Mind that professional level headphones will have a big audio jack as opposed to the small one you're used to, so you might need an adapter for your equipment. Those break easily and can actually damage your plugs, so make sure to get good ones that won't.

That all said, producing on headphones isn't really to way to go. A good set of studio monitors (you can get a set of Yamaha HS50m or KRK RP5's for around 200€ on ebay) will help you far more when it comes to producing, mixing and mastering, because headphones don't create a proper stereo image (why would take a while to explain), barely ever have a true flat frequency response, and simply are physically not able to recreate the lowend properly. But it's your choice.

For now I just want some decent headphones. I'll get to better equipment later. Maybe after I released Perfect Chaos. I'll be sure to check out those brands then as well. I already found a model from Sennheiser that seems good for a fair price. In fact, it has some sort of "best buy" mark on top. xD Looks like I unintentionally found exactly what I was looking for. xD

Subsonic_Noise

For that price you could get a used pair of Yamaha HS50m or KRK RP5, that would actually help your mixes. But your decision.

In that price area, all you'll get is "not as bad". None of them will be really flat at all. If it has to be around 100 dollars though, the KRK KNS 6400 looks pretty acceptable. It's superior to the Sennheiser in every aspect, and especially the squarewave response looks exceptionally nice for the price.

Subsonic_Noise

Well, the DJ in the name already implies that you'll have far too much bass and highs and nearly no mids.I don't know. Except for the KRKs, there's barely any headphones with a flat frequency response in tha price area. If you really want to enhance your music production, you should wait until you can affort better ones. None of these will really enhance anything.